Thanks ScottM. Here is some feedback for anyone who has a similar problem. It turned out that the Camshaft Position sensor fault was triggering both the service engine light and the flashing Trac Off light. That answered my question about whether or not the Camshaft Position sensor supplied input into the Traction Control.
The fix was a lot more complicated than I expected. The CMP fault was due to the magnet inside the sensor coming adrift from the cover. The loose magnet fouled the rotor inside the base, which bent from the impact, then destroyed the rest of the inside of the sensor. I ended up with many bits inside the sensor and no way of fitting the new sensor because of the bent rotor.
Removing the base to repair the rotor involved dismantling much of the top of the engine and removing the upper and lower cowl covers, purely to get enough clearance for the long shaft and gear that extend into the engine below the base.
I straightened the bent rotor as much as possible so that there was no conflict with the new sensor. After all of the dismantling and re-assembly, I was very relieved that the problem lights were both off when I restarted the engine.
Monday, August 27th, 2007 AT 9:17 PM